Treatment of casein fibers



Patented D...3,1946

TREATMENT or oAsnns-mnnns John E. Conrad, Alton, 111., asslgnor to Collins 8; Aikman Corporation, Philadelphia, ,Pa., a corpoi-ation of Delaware JNo Drawing. Original application october 18,

1941, Serial No. 415,631.

Divided and this application March 19, 1946, Serial No. 655,592

I I This invention relates to a process of preparing synthetic fibers derived from casein or from other protein substances for dyeing in certain' dyebaths so that these synthetic fibers, may be blended or otherwise used together with-wool and/or mohair fibers in the manufacture of textile fabrics which are to be dyed in the piece to a substantially uniform shade without objectionably noticeable striations appearing". My improvements are of particular utility in the union dyeing of fabrics, both pile and fiat, containing cotton or other cellulose fibers as well as wool and/or mohair. By my improvements a novel a Claims. (c1. 28 -74) -When untreated synthetic casein fibers are included in the pile yarn blend together with wool and/or mohair, and the fabric union-dyed in a pad dyeing operation, the synthetic casein fibers will ordinarily dye much darker or deeper than the wool and mohair fibers. As indicated herefiber and fabric are produced. This application is a division of my prior application, Serial vNo. 415,631, filed October 18, 1941.

Throughout this specification the term "caseinfibers will for brevitybe used, but the term will be understood to include other synthetic protein fibers such as those derived from the soy bean or from zein (corn), as well as those derived from casein.

Synthetic casein fibers are of protein material and accordingly have aflinity for many of the. same dyes as have wool and mohair, but the initial aflinity of the synthetic casein fibers for dyestuffs is much stronger than that of the wool and mohair fibers.- Consequently, if untreated casein fibers be blended with wool and/ or mohair fibers in yarns which are then dyed by short time immersion methods, asin pad dyeing, the casein fibers will dye so much darker than the wool and mohair as to constitute a difference in colbr.

Where the time of immersion is long, as in kettledyeing, the stronger initial afiinity of the synthetic casein fibers will be partially overtaken but there will nevertheless be a substantial difference in shade between the synthetic casein and the natural wool and/or mohair fibers.

In the manufacture in quantity of textile pile fabrics having a cotton backing or base portion and wool, or mohair, or blends thereof, with or without other fibers, including casein fibers, in the pile, it is very desirable for reasons of speed and economy of production to dye the fabric in the piece in a union dye bath in a continuous operation using pad dyeing methods. A union dye bath which I contemplate isan aqueous bath containing (a) neutral dyeing acid dyestuffs for the wool, casein and mohair fibers, and (b) substantive dyestuffs intended primarily for the cotton fibers. The wool, casein and mohair fibers also have afiinity'for the substantive dyestuffs so that the shade or color to which they dye is the combined effect of both components of the union dye bath.

repeated immersions, but there will nevertheless be a substantial contrast in shade.

A diflerence in color or shade will also occur if untreated synthetic casein fibers be blended withv According to my improvements I may produce Z a treated casein fiber which will dye to a shade approximating that of wool or mohair when the two types of fibers are dyed together ina substantially neutral aqueous union bath containing neutral dyeing acid dyestuffs and substantive dyestuffs using either short time immersion meth-- ods, as in pad dyeing, or long time repeated immersion methods, as in kettle dyeing. My treated casein fiber will also dye similarly to wool or mohair when the two typeslare dyed together by either pad or kettle. methods in a substantially neutral aqueous bath containing only neutral dyeing acid dyestuffs or when the two types are pad dyed together with vat dyestuffs. My treated casein fiber does not, however, dye like wool or mohair when the two are dyedtogether by either pad or kettle methods in acid dye baths.

\ The treatment given the casein fiber to accomplish the foregoing effects does-not weaken the fiber nor does it make the fiber stiff or hard or harsh or gummy. Inrother words, the treated fiber retains substantially its initial strength, fiexibility, elasticity and feel.

My method comprises a two bath treatment whereby a water insoluble metallic tannate is incorporated with the casein fiber. The tannate is preferably light colored so as to affect as little as possible the color or shade to which the fiber is dyed. This is important in connection with producing shades currently used for most automobile upholstery pile fabrics.

According to a preferred embodiment of my improvements, the casein fibers are first subjected to an aqueous solution of,'tannic acid. The excess solution may then be removed and the fibers next immersed in an aqueous solution,

preferably of stannous chloride, whereby tin tan- 1 hate is incorporated with the fibers. The fibers may then be rinsed and dried. The second bath f mam be incorporated with the fibers. A small amount of acetic acid may preferably be used in eachbath, the presence of acetic acid being more important inthe second bath than in the first. The time of immersion, the temperature of the baths and the concentration of the solutions will be more fully described hereinafter. I

It is an object of this invention to prepare synthetic fibers derived from casein or other protein substances for dyeingso that the said. synthetic fibers may be blended or otherwise used together with wool and/or mohair and cotton fibers and dyed in a union bath without objectionably noticeable striations appearing.

More specifically, it is an object of this invention to prepare artificial fibers derived from casein for dyeing in a union bath containing neutral dyeing acid dyestuffs and substantive. dyestufis, or for dyeing with neutral acid dyestuffs,

. or with vat dyestuffs using short time immersion dye to a shade approximating the shade of wool fibers subjected to the' same dye bath for the same length of time under the same conditions.

Another object is to provide a method of incorporating a waterinsoluble tannate with the I casein fiber.

, weight of the stock. lrtemperature substantially I higher than 120 1''. would damage the available casein fibers, and a substantialh lower temperature would give markedly inferior resist elects 5 for the contemplated dyebaths. Acetic acid in an amount approximating one per cent. of the weight ofthe stock may be contained in-the second bath. As a result of the reaction between the tannic acid and the stannous chloride, tin tannate is'incorporated with the fibers.

The metallic salt of the'second bath may, if desired, be aluminum sulphate or aluminum acetate, in which case aluminum tannate is incortimony tannate are all light in color and accord ingly will not substantially darken the natural color of the casein fiber so as to interfere with or limit the color or shade which it is desired to apply in the subsequent dyeing operation.

In each bath the volume of aqueous solvent should be sufilcien't to work the fiber stock there- 5 in. The weight of the aqueous solution may conveniently be about fifteen times the weight of thefiberstock.

Attention is. directed to theiac't that in the preferred treatment deseri a'ibovethetempero ature of the tannic acid ha is approximately 160 F. This temperature is just above the point where. the casein fibers swell markedly and at this temperature the fibers will absorb the tannic acid solution more readily than at substantially lower temperatures. Temperatures below 160 1'.

may beemployed' if desired. but the timev of immersion should be increased accordingly.

employed, but temperatures substantially in ex- Another object is 'to produce a uniformly dyed 40 cess of 180 F. should not beused, as the strength textile fabric including casein, cotton and other cellulose fibers, and wool fibers, said casein fibers having a water insoluble metallic tannate incorporated therewith.

Another object is to incorporatetin tannate, or aluminum tannate, or antimony tannate, with the casein fiber, whereby the fiber will have an aifinityz approximating that of wool fibers for neutral dyeing acid dyestuffs, or substantive dyestuifs, or both as in union dyeing.

Another object is to treat casein fibers so that they may be blended together with wool and/or mohair fibers in the pile of pile fabrics having a cotton backing, and dyed together therewith in a union bath using short time immersion methods as in continuous pad dyeing, all of the blended fibers in the pile b eing dyed to nearly the same shade.

These and other objects of invention will be I manifest from a consideration of the specification and of the claims.

According to a preferred embodiment of my invention, the syntheticcasein fibers are immersed in one quarter of one .per cent. aqueous solution of tannic acid at160 F'. It is desirable but not essential that the solution contain a small quantity ofacetic acid. After about five or more minfive or more minutes in the secondbath, which is preferably an aqueous solution, at approxi: mately 120 F., containing stannous chloride in an amount approximating three per cent. of the of the casein fibers win'be impaired. I have obtainedsatisfactory resist effects using as a first cated, this is a maximum temperature and a two minute immersion period is minimum, as shorter periods of immersion do not give sufllciently strong resist efiec'ts.

I The time of immersion in the second bath should, as indicated above, .be five minutes or more and the amount of stannous chloride in solution should neither greatly exceed nor be greatly less than three per cent. of the weight oi the fibers being. treated, as in either case the shade of the dyewould be adversely affected, and if more is used the fibers may be weakened. My improvements are particularly applicable for pad type union dyeing where the time of immersion is very short, that is, amatter of seconds. This typeof dyeing is widely used in the production of pile fabrics, as is. set forth in United States Patem to Drobile et a1. No.'2,071,922. A satisfactory dyebath immersion time'in processing according to the prior patent is ten seconds. I have found that after a ten second immersion my treated casein fibers will approximate the shade of wool I and/or, mohair blended therewith. ,It is to be understood that wool and mohair do not dye identically, but that they dye sufilciently close in shade to permit blending wtihout objectionably noticeable strlations in the finished piece. -My

- treated casein fibers may be brought within a shade range which permits blending with wool or mohair to give a like uniform appearance to the Higher temperatures than F. may also be i cloth after a ten second immersion as set forth. This result is accomplished by the treatment illus hated by this preferred embodiment.

A typical treatment of a commercial quantity of casein fibers according to my method is as follows:

500 lbs. of synthetic casein fibers is placed in a suitable container or kettle. The aqueous so-- lution of tannlc acid at about 135 F. is drawn from a reservoir, placed in the kettle and then brought to a temperature of 160 F. and held there for approximately ten minutes, during which the fiber stock may be gently agitated. The tannic acid solution is then drained out and pumped back into the reservoir. A light rinse may then be given the casein. fibers, after which any excess water or solution may be removed. The fibers are now ready for the second bath. Water and half of the required acetic acid is poured into the kettle, then the solution of stannous chloride and the remainder of the acetic acid is added and the entire solution brought to 120 F. and held there. The fibers are kept in this solution for approximately five minutes, after which the kettle is drained, the fibers rinsed and then dried. In this condition the fibers are ready for blending with wool or other fibers or for use alone in'the formation of yarns.

As indicated hereinbefore, casein fibers treated according to my methods will dye approximately like wool when the two types of fibers are dyed together, by either pad or kettle-methods, in a substantially neutral aqueous medium containing neutral dyeing acid dyestuffs or substantive dyestufis, or both as in union dyeing, 0r pad dyed with vat dyestuffs. Casein fibers treated according to my method will not, however, dye like wool where the two are immersed together in an acid bath containing acid dyeing acidv dyestuffs.

Having described my invention, I claim:

1. In a process'of making pile fabrics which contain natural staple animal fibers and synthetic fibers derived from casein in th pile portion, the steps which include treating the synthetic fibers derived from casein so as to incorporate a light colored metallic tannate in the fibers, blending the casein fibers with the natural animal fibers,

' and fabricating said blended fibers into the pile portion of a pile fabric and then pad dyeing the animal and synthetic fibers of the pile to approximately the same shade.

2. Ina process of making pile fabrics which contain natural animal fibers and synthetic fibers derived from casein in the pile portion, the steps which include treating the synthetic fibers derived from casein so as to incorporate a light colored metallic tannate in the fibers, blending the treated casein fibers with the natural animal fibers and fabricating said blended fibers into the pile portion of a pile fabric having a cotton backing, and then pad dyeing the pile fabric to approximately a uniform shade in the pile portion.

3. In a process of making pile fabrics the pile portion of which contains natural staple animal fibers and synthetic fibers derived from casein, the steps which consist of treating the synthetic fibers so as to incorporate a light colored metallic tannate in the fibers. blending the casein fibers with the natural animal fibers and fabricating the blended fibers into the pile portion of apile fabric, and then dyeing both types of said pile fibers to approximately the same shade by the use "of a neutral dye bath containing neutral dyeing acid colors.

taining natural staple animal fibers and synthetic fibers derived from casein in the pile portion, the steps which consistof treating the synthetic fibers derived from casein so as to incorporate a light" colored metallic tannatein the fibers, blending the casein fibers with the natural animal fibers, and fabricating said blended fibers into the pile portion of a pile fabric having a cellulose backing, and thendyeing the animal and synthetic fibers to approximately the same shade with a neutral dye bath containing neutral dyeing acid colors and substantive dyes.

5. A process of making pile fabrics of approximately uniform shade which includes the steps of treating synthetic fibers derived from casein so as to form a light colored metallic tannate in the fiber, blending the casein fibers with natural animal staple fibers and forming a yarn, fabricating said yarn into the pile portion of a pile fabric and piece dyeingth pile face to an approximately uniform shade with a substantially neutral-dye bath containing neutral dyeing acid colors. v

6. A process. of making pile fabrics of approximately uniform shade in the face portion, which process includes the steps of treating synthetic fibers derived from casein so as to form a light colored metallic tannate in the fibers, blending the casein fibers with natural animal staple fibers and forming a yarn, fabricating said yarn into the pile portion of a pile fabric having a cotton backing and union piece dyeing the pile fabric to an approximately uniform shade with a neutral dye bath containing neutral dyeing acid colors and substantive dyes. j

7. A process of making pile fabric having a pile portion of approximately uniform shade which includes the stepsof treating synthetic fibers derived from casein so as to form a light colored metallic tannate in the fibers, blending the casein fibers with natural animal staple fibers and forming a yarn, fabricating said yarn into the pile portion of a pile fabric, and pad dyeing the pile fibers to an approximately uniform shade with a substantially neutral dye bath containing neutral dyeing acid colors. 7

8. A process of making pile fabric having a ,pile portion-of approximately uniform shade,

which includes the steps of treating synthetic fibers derived from casein so as to form a light colored metallic tannate in the fibers, blending the casein fibers with natural animal fibers and forn'iing a yarn, fabricating said yarn into the pile portion of a pile fabric having a cotton backing and union pad dyeing the pile fabric to an approximately uniform shade with a substantially neutral dye bath containing neutral dyeing acid colors and substantive dyes.

9. A processof making pile fabrics of approxi- 6 mately uniform shade which includes the steps of treating synthetic fibers derived from casein so as to form a tin tannate on the fibers, blending the casein fibers with natural animal fibers and forminga yarn, forming a fabric having a cotton base portion and a pile portion of the blended yarn and dyeing the entire fabric to approximately the same shade with a substantially neutral dye bath containing neutral dyeing acid colors and substantive dyestuffs. v

10. A process asset forth in claim 9, further characterized in that the tin tannate is formed by treating the casein fibers with each of two separate solutions, onejof which contains tannic acid and the other of which contains a' tin salt. JOHN E. CONRAD. 

